class Solution {
public:
    vector<int> searchRange(vector<int>& nums, int target) {
        if(nums.size() == 0)
            return {-1, -1};
        int left = 0, right = nums.size() - 1;
        while(left < right) // 找左端点
        {
            int mid = left + (right - left) / 2;
            if(nums[mid] < target)
                left = mid + 1;
            else
                right = mid;
        }
        if(nums[left] != target) // 没有端点的情况
            return {-1, -1};
        int tmp = left;

        right = nums.size() - 1; // 找右端点
        while(left < right)
        {
            int mid = left + (right - left + 1) / 2;
            if(nums[mid] > target)
                right = mid - 1;
            else
                left = mid;
        }
        return {tmp, right};
    }
};
/*
class Solution {
public:
    vector<int> searchRange(vector<int>& nums, int target) {
        if(nums.size() == 0)
            return {-1, -1};

        auto it = lower_bound(nums.begin(), nums.end(), target); // 找第一个大于等于target的位置
        int left = (it == nums.end() || *it != target) ? -1 : it - nums.begin();
        if(left == -1)
            return {-1, -1};
            
        it = upper_bound(nums.begin(), nums.end(), target); // 找第一个大于target的位置
        int right = it - nums.begin() - 1;
            return {left, right};
    }
};
*/